Improvement in let-off mechanisms for looms



N. PETERS. FHOTQ-LIYHOGRAPHEE, WASHINGTON. D C.

UNITED STATES PATENT OFFICE.

WILLIAM THOMAS FLINN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO HIMSELF AND JACOB STEINMETZ THORN, OF SAME PLACE.

IMPROVEMENT IN LET-OFF MECHANISMS FORLOOMS.

Specification forming part of Letters Patent No. l 13,415, dated April 4, 1871.

To all whom it 71mg/ concern:

Be it known that l, WILLIAM TI-IoMAs FLINN, of Philadelphia. county ol'l Philadelphia, State of Pennsylvania, have invented a Let-Off Device for Looms, of which the following is aspeciiication. l

My invention consists of a warp-beam for looms, having its bearings in clamps constructed, as fully described hereinafter, so that more or less friction may be imparted to the beam.

The object of my invention is to maintain a uniform tension on the warp-threads and to regulate theaniount of tension at pleasure.

In the accompanying drawings, Figure 1 is a vertical section of sufficient of a loom to illustrate my improvement, and Fig. 2 a plan View of the same.

A and A represent the opposite side frames of a loom; B, the breast beam, and l) the warp-beam or roller. This warp-beam has the usual journals, et a, but these do not revolve in-the ordinary bearings in the frame, but in Vertical slots, which serve only to retain the beam in a' proper lateral position, its vert-ical support depending on clamps E and E, hinged to brackets b on the rear cross-bar of the frame. There are two of these clamps. one adapted to a` grooved pulley, G, secured to the beam near one end ofthe saine, and the other to a si milar pulley, G', at the opposite end of the beam, each clamp consisting of a segment provided with a lip, e. These segments are caused to grip their pulley with more or less forcein the present instance by a rod, H, having a screw-thread adapted to the lip e of one segnient and arranged to turn freely in the lip of the other segment, the rod being confined longitudinally to this lip by suitable collars, so that on turning the rod in one direction the clamp will be contracted and grip the pulley, and on turning it in the opposite direction the clamp will be opened, and` this opening may be aided .by a suitable springsituated between the projections e of the segments.

It will be seen that the lower curved end of each segment extends beyond the pin b on which the segment is hung, and therefore that the vertical pressure of the beam bearing on these ends ofthe segment-s will cause the segments to grasp the pulleys with a pressure corresponding to t-he weight of the beam. the

Vfriction being greatest when the warp-beam is full and heaviest, and when the leverage eX- erted to turn the beam by the take-u p motion is greatest, and the weight, and consequently the friction, decreasing as the warp-threads are drawn off, theleverage, owing to the diminution in the diameter of the beam, becomes r less; hence I have termed the device a compensating let-oi device, by which a uniform tension of the warp-threads is maintained.

More 0r less tension may be readily i'mparted to the warp-threads by turning the rods H, and thereby causing the clamps to embrace the pulleys with more or less force.

I do not desire to contine myself to the precise arrangement and construction of parts herein described; but

I claiml The combination ofthe clamps and the warp-beam resting thereon, the said clamps being constructedsubstantially as described, so that the pressure of the beam upon the lower ends of the clamps will cause them to grasp the beam.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

V. T. FLINN.

Witn esses:

THos. MCILVAIN, HARRY SMITH. 

